1. Field of the Invention
This invention relates to a method for graphically displaying an automation application programmed on a programming station using graphic automation languages, on a computer terminal. The invention also relates to a computer terminal capable of graphically displaying an automation application programmed on a programming station using graphic automation languages.
2. Description of the Related Art
In the following, a programming station means a computer equipment, particularly a PC type personal computer, that can be connected to an automation equipment and on which software is installed for designing an automation application program using graphic automation languages.
In the following, an automation equipment means a programmable logic controller, an instrumentation/control station, a digital control or any equipment that can contain and execute an application program for controlling/monitoring an automation application. For example, this automation application may belong to the field of industrial automation, building automation or instrumentation/control of electrical distribution networks. This type of automation equipment can be composed of a central processing unit and one or several input/output couplers connected to sensors and preactuators of the industrial process to be controlled.
The central processing unit of an automation equipment comprises at least one processor, a non-volatile and usually non-modifiable memory (ROM type), or possibly a modifiable memory (EEPROM type), containing the manufacturer's program also called a proprietary operating system expressed in a language specific to the manufacturer of the automation equipment, a RAM memory and an inputs/outputs manager that communicate with each other through a back panel bus. The RAM or volatile memory contains the user program in a first area, and the data in a second area, particularly images of the states of input/output couplers and constants for the user's program.
The user program, also called the application program, is responsible for monitoring and/or controlling an automation application through inputs/outputs driven by this application program. It is generated by a designer and is written in one or several graphic automation languages, particularly including a Ladder diagram language, hereinafter referred to as the Ladder language, a Sequential Function Chart or grafcet language, hereinafter called the SFC language, a Function Block Description language, hereinafter called the FBD language, or in one or several automation text languages of the IL (Instruction List) or ST (Structured Text) type. These automation languages advantageously conform with the IEC1131-3 standard so as to facilitate programming by an automation designer who is not necessarily familiar with computer languages. These languages can be used on programming stations that may or may not be connected to the automation equipment to be programmed.
At the moment, automation applications created through the use of graphic automation languages according to the IEC1131-3 standard (Ladder, Grafcet, FBD, IL Instruction List, ST Structured Text) can only be displayed on a programming station on which the programming software for an application is installed. But this software is sometimes expensive and voluminous. Consequently, it cannot be installed on all computer terminals. Therefore, a technician using an automation application and who would like to be able to take action as soon as a malfunction on an automation equipment occurs, cannot graphically display his application program without making use of a programming station on which the programming software for the application is installed.
Therefore, the purpose of this invention is to overcome these disadvantages according to prior art by proposing a solution that in particular enables a technician to graphically display or to graphically print his application program from any computer terminal on which the installed software is not specific to the automation world.
This purpose is achieved by a method for graphically displaying or printing an automation application programmed on a programming station using graphic automation languages (LD, SFC, FBD), on a computer terminal comprising at least one processor and storage means. The method comprises:                a storage step on the terminal, to store a source program of an automation application formulated using a graphic automation language (LD, SFC, FBD), the source program being written in a unique hierarchised and object oriented language representing at least one graphic automation language (LD, SFC, FBD),        a storage step on the terminal to store at least one stylesheet associated with the graphic language used for development of the automation application,        a processing step to process the source program on the terminal using the stylesheet to generate a graphic vector file containing directives of graphic vector drawing to enable graphic display of the automation application on the terminal, or to print it graphically.        